1. Field of the Invention
The invention relates to image processing apparatus and method for adding predetermined information to an input image and a storage medium in which such a method has been stored.
2. Related Background Art
Hitherto, an image recording apparatus such as an ink jet printer or the like forms a color image by ink, toner, or the like of four colors of CMYK.
In recent years, however, an ink jet printer such that not only the inks of four colors of CMYK mentioned above but also light inks of the same color system of the above respective colors are simultaneously used, thereby enabling a printing of three or more values to be performed for each color has been developed. Such an ink jet printer can form a color image of a higher image quality of higher gradation than those of the conventional ink jet printer using the inks of four colors.
In association with the realization of such a high image quality, the formation of an image which is almost similar to an original in which a copy or an image formation is inhibited is becoming possible by using the recent image recording apparatus.
To deter such an illegal image formation, a technique such that addition information to specify an image forming apparatus or an operator is embedded to all of the formed images by a form such that it is difficult to be discriminated by the human eye has been known. For example, a technique such that among the image forming colors (CMYK) of a copying apparatus, by changing an image signal of the yellow component which is the most difficult to be discriminated by the human eye, a pattern showing a manufacturing number or the like of the copying apparatus is embedded is disclosed in U.S. Pat. No. 5,257,119.
However, hitherto, with respect to a case of forming a color image by using a plurality of kinds of inks, toners, or the like having different densities in the same color system, an optimum method of embedding addition information to an input image is not yet realized.